Light

Question 1

What is a luminous object ?

Answer 1

A light source

Something that produces its own light

For example : Sun ,Burning candle

Question 2

What is a non-luminous object ?

Answer 2

An object that does not produce its own light

Question 3

What are the two laws of reflection ?

Answer 3

1. The angle of incidence = The angle of reflection

2. The incident ray, reflected ray and the normal will always be on the same plane

Question 4

How do we see non-luminous object ?

Answer 4

We are able to see non-luminous objects because it reflects the light from luminous objects into our eyes. In other words “the reflection of light”

Question 5

Is moon a luminous or non-luminous object ?

Answer 5

The moon is a non luminous object

The reason why we see it is because it reflects light from the sun into our eyes

Question 6

What is the symbol of the angle of incidence ? Or incident ray

Answer 6

i

Question 7

How do we define a ray of light ?

Answer 7

A straight line path which light travels

Question 8

Which direction does luminous object emit their light ?

Answer 8

They emit light all possible directions

Question 9

what is the symbol for the angle of reflection ?

Answer 9

r

Question 10

How does light travel ?

Answer 10

Light travels in a straight line

Question 11

What is the speed of light in seconds ?

Answer 11

300,000 km/sec

Question 12

What is refraction ?

Answer 12

The bending of light when it enters a different medium

Question 13

What is apparent depth ?

Answer 13

How deep something appears to be

Question 14

What is real depth

Answer 14

How deep something actually is

Question 15

What is dispersion ?

Answer 15

The splitting of white light into a spectrum of colors

Question 16

What is a prism ?

Answer 16

A transparent object that refracts light

Question 17

What are the colors in a spectrum ?

Answer 17

Red 
Orange 
Yellow 
Green 
Blue 
Indigo 
Violet

Question 18

What are the primary colors?

Answer 18

Red blue and green

Question 19

What are the secondary colors ?

Answer 19

Yellow , magenta , cyan

Question 20

What happens when you mix all the primary colors ?

Answer 20

It will make white

Question 21

Why is white and black not part of the colour spectrum ?

Answer 21

White = combination of all the colors

Black = the absence of light

Question 22

which colour has the longest wavelength ?

Answer 22

Red has the longest wavelength

Question 23

Which color has the shortest wavelength ?

Answer 23

Violet has the shortest wavelength

Question 24

What is the relationship between wavelength and frequency ?

Answer 24

Longer the wavelength = Shorter the frequency

Shorter the wavelength = higher frequency

Question 25

Which particular color and object appears depends on what ?

Answer 25

The color that is reflected into out eyes

The properties of the object

Question 26

When light touches and object its either ?

Answer 26

1. Reflected
2. Absorbed
3. Transmitted

Question 27

When light touches a opaque object what happens ?

Answer 27

It’s either reflected or absorbed

Question 28

Why do we see color in a object

Answer 28

Because the object is reflecting the particular colors wavelengths of light and absorbing all the other colors .

Question 29

When light hits an transparent object what happens ?

Answer 29

All of the light is transmitted with only small amount being absorbed or reflected

Question 30

When light hits a translucent object what happens ?

Answer 30

It only transmits some of the light

Question 31

How is the color of an translucent object determined

Answer 31

Determined by which colour is transmitted the most